This section is intended to provide a background or context to the invention recited in the claims. The description herein may include concepts that could not be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
Power shovels are in a category of excavation equipment used to remove large amounts of overburden and ore during a mining operation. One type of power shovel is known as a rope shovel. A rope shovel includes a boom, a dipper handle pivotally connected to a mid-point of the boom, and a dipper (also known as a shovel) pivotally connected at one end of the dipper handle. A cable extends over a pulley at a distal end of the boom and terminates at the end of the dipper handle supporting the dipper. The cable is reeled in or spooled out on a hoist drum, the hoist drum being powered by electric, hydraulic, and/or mechanical motors to selectively raise and lower the dipper.
The power shovel may also include auxiliary weights. The auxiliary weights serve as ballast to offset the weight of ore that may be carried in the dipper. Adding additional auxiliary weights to the power shovel is desirable in that it may increase the amount of ore that can be carried by the dipper. However, adding additional auxiliary weights to the power shovel also makes the power shovel heavier which results in increased fuel usage and can inhibit the power shovel from entering areas where the ground is soft.
One example of a power shovel having auxiliary weights serve as ballast is U.S. Pat. No. 4,608,743 titled “MINING SHOVEL BALLAST BOX CONNECTION METHOD AND APPARATUS”. The '743 patent indicates that a large ballast box may be attached to the main rotating body of a power mining shovel. The '743 patent further describes that the ballast box may weigh several hundred thousand pounds and serves as a counterweight to all of the forces generated on a forward end of the power mining shovel.